MANHATTAN - The National September 11 Memorial Museum opens to the public on May 21, but a "Dedication Period" for families begins this week, and the media -- including the Advance -- will get a look at the long-awaited museum Wednesday.

Those who helped guide the museum to its opening some 12-and-a-half years after the Sept. 11, 2001 terrorist attacks -- including former Mayor Michael Bloomberg, president of the museum's board and someone who steered millions of dollars in its direction -- will also an overview of the museum Wednesday morning.

Wednesday will offer an early look at what's been in the works for so long -- and a glance at a place that is sure to be both deeply personal for those touched by the events of Sept. 11 and educational for generations to come.

An "In Memoriam" exhibit will not be open Wednesday, to allow families to visit it first.

On Thursday, the museum will be dedicated - an event President Barack Obama and First Lady Michelle Obama will attend.

Then the Dedication Period will begin -- and the museum will be open from Thursday through May 20 only to victims' family members, rescue and recovery workers, active duty first responders, 9/11 survivors, Lower Manhattan residents and business owners and World Trade Center rebuilding partners.

The museum hasn't been without controversy -- there have been complaints about how long it took to build, concerns from family members about its sensitivity to remains at the site, and most recently, consternation over the decision to charge admission to the general public when the museum opens.

Check SILive.com throughout the day Wednesday for coverage of the museum, and on Thursday for coverage of its dedication.